diff --git a/cms/envs/test.py b/cms/envs/test.py
index f3eee45ea7..77c05d9fa4 100644
--- a/cms/envs/test.py
+++ b/cms/envs/test.py
@@ -25,7 +25,6 @@ _report_dir = REPO_ROOT / 'reports' / _system
 _report_dir.makedirs_p()
 
 NOSE_ARGS = [
-    '--tests', PROJECT_ROOT / 'djangoapps', COMMON_ROOT / 'djangoapps',
     '--id-file', REPO_ROOT / '.testids' / _system / 'noseids',
     '--xunit-file', _report_dir / 'nosetests.xml',
 ]
diff --git a/lms/envs/test.py b/lms/envs/test.py
index 0951601ec7..63ff830c92 100644
--- a/lms/envs/test.py
+++ b/lms/envs/test.py
@@ -51,7 +51,6 @@ _report_dir = REPO_ROOT / 'reports' / _system
 _report_dir.makedirs_p()
 
 NOSE_ARGS = [
-    '--tests', PROJECT_ROOT / 'djangoapps', COMMON_ROOT / 'djangoapps',
     '--id-file', REPO_ROOT / '.testids' / _system / 'noseids',
     '--xunit-file', _report_dir / 'nosetests.xml',
 ]
diff --git a/rakelib/tests.rake b/rakelib/tests.rake
index ba436f3680..130ff3d9fd 100644
--- a/rakelib/tests.rake
+++ b/rakelib/tests.rake
@@ -17,7 +17,19 @@ def run_under_coverage(cmd, root)
 end
 
 def run_tests(system, report_dir, test_id=nil, stop_on_failure=true)
-    test_id = '' if test_id.nil?
+
+    # If no test id is provided, we need to limit the test runner
+    # to the Djangoapps we want to test.  Otherwise, it will
+    # run tests on all installed packages.
+    if test_id.nil?
+        test_id = "#{system}/djangoapps common/djangoapps"
+
+    # Handle "--failed" as a special case: we want to re-run only
+    # the tests that failed within our Django apps
+    elsif test_id == '--failed'
+        test_id = "#{system}/djangoapps common/djangoapps --failed"
+    end
+
     cmd = django_admin(system, :test, 'test', test_id)
     test_sh(run_under_coverage(cmd, system))
 end